Reimplement the Parser and VM with a register-based VM

dust-lang/src/chunk.rs

@@ -181,21 +181,20 @@ impl Chunk {
         let name_length = name.len();
         let buffer_length = 34_usize.saturating_sub(name_length + 2);
         let name_buffer = " ".repeat(buffer_length / 2);
-        let name_line = format!("\n{name_buffer}{name}{name_buffer}\n");
+        let name_line = format!("{name_buffer}{name}{name_buffer}\n");
         let name_underline = format!("{name_buffer}{}{name_buffer}\n", "-".repeat(name_length));
 
         output.push_str(&name_line);
         output.push_str(&name_underline);
         output.push_str("\n              Code              \n");
-        output.push_str("------ ------------ ------------\n");
+        output.push_str("------ -------- ------------\n");
         output.push_str("OFFSET POSITION INSTRUCTION\n");
-        output.push_str("------ ------------ ------------\n");
+        output.push_str("------ -------- ------------\n");
 
         for (offset, (instruction, position)) in self.code.iter().enumerate() {
             let display = format!(
-                "{offset:4}   {:12} {}\n",
+                "{offset:04}   {position}   {}\n",
-                position.to_string(),
+                instruction.disassemble(self)
-                instruction.disassemble(self, offset)
             );
 
             output.push_str(&display);

dust-lang/src/dust_error.rs

@@ -1,6 +1,6 @@
 use annotate_snippets::{Level, Renderer, Snippet};
 
-use crate::{LexError, ParseError, Span};
+use crate::{vm::VmError, LexError, ParseError, Span};
 
 #[derive(Debug, PartialEq)]
 pub enum DustError<'src> {
@@ -12,6 +12,10 @@ pub enum DustError<'src> {
         error: ParseError,
         source: &'src str,
     },
+    Runtime {
+        error: VmError,
+        source: &'src str,
+    },
 }
 
 impl<'src> DustError<'src> {
@@ -20,6 +24,20 @@ impl<'src> DustError<'src> {
         let renderer = Renderer::styled();
 
         match self {
+            DustError::Runtime { error, source } => {
+                let position = error.position();
+                let label = format!("Runtime error: {}", error.description());
+                let details = error
+                    .details()
+                    .unwrap_or_else(|| "While running this code".to_string());
+                let message = Level::Error.title(&label).snippet(
+                    Snippet::source(source)
+                        .fold(true)
+                        .annotation(Level::Error.span(position.0..position.1).label(&details)),
+                );
+
+                report.push_str(&renderer.render(message).to_string());
+            }
             DustError::Parse { error, source } => {
                 let position = error.position();
                 let label = format!("Parse error: {}", error.description());

dust-lang/src/instruction.rs

@@ -1,16 +1,18 @@
+use std::fmt::{self, Display, Formatter};
+
 use crate::{Chunk, Span};
 
 #[derive(Clone, Copy, Debug, PartialEq)]
 pub struct Instruction {
-    opcode: OpCode,
+    pub operation: Operation,
-    to_register: u8,
+    pub to_register: u8,
-    arguments: [u8; 2],
+    pub arguments: [u8; 2],
 }
 
 impl Instruction {
     pub fn r#move(to_register: u8, from_register: u8) -> Instruction {
         Instruction {
-            opcode: OpCode::Move,
+            operation: Operation::Move,
             to_register,
             arguments: [from_register, 0],
         }
@@ -18,7 +20,7 @@ impl Instruction {
 
     pub fn close(to_register: u8) -> Instruction {
         Instruction {
-            opcode: OpCode::Close,
+            operation: Operation::Close,
             to_register,
             arguments: [0, 0],
         }
@@ -26,7 +28,7 @@ impl Instruction {
 
     pub fn load_constant(to_register: u8, constant_index: u16) -> Instruction {
         Instruction {
-            opcode: OpCode::LoadConstant,
+            operation: Operation::LoadConstant,
             to_register,
             arguments: constant_index.to_le_bytes(),
         }
@@ -34,7 +36,7 @@ impl Instruction {
 
     pub fn declare_variable(to_register: u8, variable_index: u16) -> Instruction {
         Instruction {
-            opcode: OpCode::DeclareVariable,
+            operation: Operation::DeclareVariable,
             to_register,
             arguments: variable_index.to_le_bytes(),
         }
@@ -42,7 +44,7 @@ impl Instruction {
 
     pub fn get_variable(to_register: u8, variable_index: u16) -> Instruction {
         Instruction {
-            opcode: OpCode::GetVariable,
+            operation: Operation::GetVariable,
             to_register,
             arguments: variable_index.to_le_bytes(),
         }
@@ -50,7 +52,7 @@ impl Instruction {
 
     pub fn set_variable(from_register: u8, variable_index: u16) -> Instruction {
         Instruction {
-            opcode: OpCode::SetVariable,
+            operation: Operation::SetVariable,
             to_register: from_register,
             arguments: variable_index.to_le_bytes(),
         }
@@ -58,7 +60,7 @@ impl Instruction {
 
     pub fn add(to_register: u8, left_register: u8, right_register: u8) -> Instruction {
         Instruction {
-            opcode: OpCode::Add,
+            operation: Operation::Add,
             to_register,
             arguments: [left_register, right_register],
         }
@@ -66,7 +68,7 @@ impl Instruction {
 
     pub fn subtract(to_register: u8, left_register: u8, right_register: u8) -> Instruction {
         Instruction {
-            opcode: OpCode::Subtract,
+            operation: Operation::Subtract,
             to_register,
             arguments: [left_register, right_register],
         }
@@ -74,7 +76,7 @@ impl Instruction {
 
     pub fn multiply(to_register: u8, left_register: u8, right_register: u8) -> Instruction {
         Instruction {
-            opcode: OpCode::Multiply,
+            operation: Operation::Multiply,
             to_register,
             arguments: [left_register, right_register],
         }
@@ -82,7 +84,7 @@ impl Instruction {
 
     pub fn divide(to_register: u8, left_register: u8, right_register: u8) -> Instruction {
         Instruction {
-            opcode: OpCode::Divide,
+            operation: Operation::Divide,
             to_register,
             arguments: [left_register, right_register],
         }
@@ -90,7 +92,7 @@ impl Instruction {
 
     pub fn negate(to_register: u8, from_register: u8) -> Instruction {
         Instruction {
-            opcode: OpCode::Negate,
+            operation: Operation::Negate,
             to_register,
             arguments: [from_register, 0],
         }
@@ -98,84 +100,97 @@ impl Instruction {
 
     pub fn r#return() -> Instruction {
         Instruction {
-            opcode: OpCode::Return,
+            operation: Operation::Return,
             to_register: 0,
             arguments: [0, 0],
         }
     }
 
-    pub fn disassemble(&self, chunk: &Chunk, offset: usize) -> String {
+    pub fn disassemble(&self, chunk: &Chunk) -> String {
-        match self.opcode {
+        match self.operation {
-            OpCode::Move => format!(
+            Operation::LoadConstant => {
-                "{:04} MOVE R{} R{}",
-                offset, self.to_register, self.arguments[0]
-            ),
-            OpCode::Close => {
-                format!("{:04} CLOSE R{}", offset, self.to_register)
-            }
-            OpCode::LoadConstant => {
                 let constant_index = u16::from_le_bytes(self.arguments);
                 let constant_display = match chunk.get_constant(constant_index, Span(0, 0)) {
                     Ok(value) => value.to_string(),
                     Err(error) => format!("{:?}", error),
                 };
 
-                format!(
+                format!("{self} {constant_display}")
-                    "{:04} LOAD_CONSTANT R{} C{} {}",
-                    offset, self.to_register, constant_index, constant_display
-                )
             }
-            OpCode::DeclareVariable => {
+            _ => format!("{self}"),
+        }
+    }
+}
+
+impl Display for Instruction {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        match self.operation {
+            Operation::Move => write!(f, "MOVE R{} R{}", self.to_register, self.arguments[0]),
+            Operation::Close => write!(f, "CLOSE R{}", self.to_register),
+            Operation::LoadConstant => {
+                let constant_index = u16::from_le_bytes(self.arguments);
+
+                write!(f, "LOAD_CONSTANT R{} C{}", self.to_register, constant_index)
+            }
+            Operation::DeclareVariable => {
                 let variable_index = u16::from_le_bytes([self.arguments[0], self.arguments[1]]);
 
-                format!(
+                write!(
-                    "{:04} DECLARE_VARIABLE V{} R{}",
+                    f,
-                    offset, variable_index, self.to_register
+                    "DECLARE_VARIABLE V{} R{}",
+                    variable_index, self.to_register
                 )
             }
-            OpCode::GetVariable => {
+            Operation::GetVariable => {
                 let variable_index = u16::from_le_bytes([self.arguments[0], self.arguments[1]]);
 
-                format!(
+                write!(f, "GET_VARIABLE R{} V{}", self.to_register, variable_index)
-                    "{:04} GET_VARIABLE R{} V{}",
-                    offset, self.to_register, variable_index
-                )
             }
-            OpCode::SetVariable => {
+            Operation::SetVariable => {
                 let variable_index = u16::from_le_bytes([self.arguments[0], self.arguments[1]]);
 
-                format!(
+                write!(f, "SET_VARIABLE V{} R{}", variable_index, self.to_register)
-                    "{:04} SET_VARIABLE V{} R{}",
+            }
-                    offset, variable_index, self.to_register
+            Operation::Add => {
+                write!(
+                    f,
+                    "ADD R{} = R{} + R{}",
+                    self.to_register, self.arguments[0], self.arguments[1]
                 )
             }
-            OpCode::Add => format!(
+            Operation::Subtract => {
-                "{:04} ADD R{} = R{} + R{}",
+                write!(
-                offset, self.to_register, self.arguments[0], self.arguments[1]
+                    f,
-            ),
+                    "SUBTRACT R{} = R{} - R{}",
-            OpCode::Subtract => format!(
+                    self.to_register, self.arguments[0], self.arguments[1]
-                "{:04} SUBTRACT R{} = R{} - R{}",
+                )
-                offset, self.to_register, self.arguments[0], self.arguments[1]
+            }
-            ),
+            Operation::Multiply => {
-            OpCode::Multiply => format!(
+                write!(
-                "{:04} MULTIPLY R{} = R{} * R{}",
+                    f,
-                offset, self.to_register, self.arguments[0], self.arguments[1]
+                    "MULTIPLY R{} = R{} * R{}",
-            ),
+                    self.to_register, self.arguments[0], self.arguments[1]
-            OpCode::Divide => format!(
+                )
-                "{:04} DIVIDE R{} = R{} / R{}",
+            }
-                offset, self.to_register, self.arguments[0], self.arguments[1]
+            Operation::Divide => {
-            ),
+                write!(
-            OpCode::Negate => format!(
+                    f,
-                "{:04} NEGATE R{} = !R{}",
+                    "DIVIDE R{} = R{} / R{}",
-                offset, self.to_register, self.arguments[0]
+                    self.to_register, self.arguments[0], self.arguments[1]
-            ),
+                )
-            OpCode::Return => format!("{:04} RETURN", offset),
+            }
+            Operation::Negate => {
+                write!(f, "NEGATE R{} = !R{}", self.to_register, self.arguments[0])
+            }
+            Operation::Return => {
+                write!(f, "RETURN")
+            }
         }
     }
 }
 
 #[derive(Clone, Copy, Debug, PartialEq)]
-enum OpCode {
+pub enum Operation {
     // Stack manipulation
     Move,
     Close,
@@ -201,6 +216,25 @@ enum OpCode {
     Return,
 }
 
+impl Display for Operation {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        match self {
+            Operation::Move => write!(f, "MOVE"),
+            Operation::Close => write!(f, "CLOSE"),
+            Operation::LoadConstant => write!(f, "LOAD_CONSTANT"),
+            Operation::DeclareVariable => write!(f, "DECLARE_VARIABLE"),
+            Operation::GetVariable => write!(f, "GET_VARIABLE"),
+            Operation::SetVariable => write!(f, "SET_VARIABLE"),
+            Operation::Add => write!(f, "ADD"),
+            Operation::Subtract => write!(f, "SUBTRACT"),
+            Operation::Multiply => write!(f, "MULTIPLY"),
+            Operation::Divide => write!(f, "DIVIDE"),
+            Operation::Negate => write!(f, "NEGATE"),
+            Operation::Return => write!(f, "RETURN"),
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use std::mem::size_of;

dust-lang/src/lib.rs

@@ -8,6 +8,7 @@ mod parser;
 mod token;
 mod r#type;
 mod value;
+mod vm;
 
 use std::fmt::Display;
 
@@ -15,12 +16,13 @@ pub use chunk::{Chunk, ChunkError};
 pub use constructor::Constructor;
 pub use dust_error::{AnnotatedError, DustError};
 pub use identifier::Identifier;
-pub use instruction::Instruction;
+pub use instruction::{Instruction, Operation};
 pub use lexer::{lex, LexError, Lexer};
 pub use parser::{parse, ParseError, Parser};
 pub use r#type::{EnumType, FunctionType, RangeableType, StructType, Type, TypeConflict};
 pub use token::{Token, TokenKind, TokenOwned};
-pub use value::{Enum, Function, Struct, Value};
+pub use value::{Enum, Function, Struct, Value, ValueError};
+pub use vm::{run, Vm, VmError};
 
 #[derive(Clone, Copy, Debug, PartialEq)]
 pub struct Span(pub usize, pub usize);

dust-lang/src/parser/mod.rs

@@ -214,6 +214,7 @@ impl<'src> Parser<'src> {
             }
         };
 
+        self.increment_register()?;
         self.parse_expression()?;
         self.emit_instruction(byte, operator_position);
 
@@ -234,8 +235,8 @@ impl<'src> Parser<'src> {
         } else {
             self.current_register
         };
-        let left_register = to_register - 1;
+        let left_register = to_register - 2;
-        let right_register = to_register - 2;
+        let right_register = to_register - 1;
         let byte = match operator {
             TokenKind::Plus => Instruction::add(to_register, left_register, right_register),
             TokenKind::Minus => Instruction::subtract(to_register, left_register, right_register),
@@ -255,6 +256,7 @@ impl<'src> Parser<'src> {
             }
         };
 
+        self.increment_register()?;
         self.emit_instruction(byte, operator_position);
 
         Ok(())
@@ -319,19 +321,10 @@ impl<'src> Parser<'src> {
         }
 
         self.chunk.end_scope();
-
-        while self
-            .chunk
-            .identifiers()
-            .iter()
-            .next_back()
-            .map_or(false, |local| local.depth > self.chunk.scope_depth())
-        {
         self.emit_instruction(
             Instruction::close(self.current_register),
             self.current_position,
         );
-        }
 
         Ok(())
     }
@@ -392,7 +385,7 @@ impl<'src> Parser<'src> {
         let identifier_index = self.chunk.declare_variable(identifier, position)?;
 
         self.emit_instruction(
-            Instruction::set_variable(self.current_register, identifier_index),
+            Instruction::declare_variable(self.current_register, identifier_index),
             position,
         );
         self.increment_register()?;
@@ -714,7 +707,7 @@ impl AnnotatedError for ParseError {
             }
             Self::RegisterOverflow { .. } => None,
             Self::Chunk(error) => error.details(),
-            Self::Lex(error) => Some(error.to_string()),
+            Self::Lex(error) => error.details(),
             Self::ParseIntError { error, .. } => Some(error.to_string()),
         }
     }

dust-lang/src/parser/tests.rs

@@ -23,7 +23,24 @@ fn add() {
             vec![
                 (Instruction::load_constant(0, 0), Span(0, 1)),
                 (Instruction::load_constant(1, 1), Span(4, 5)),
-                (Instruction::add(2, 1, 0), Span(2, 3)),
+                (Instruction::add(2, 0, 1), Span(2, 3)),
+                (Instruction::r#return(), Span(0, 5)),
+            ],
+            vec![Value::integer(1), Value::integer(2),],
+            vec![]
+        ))
+    );
+}
+
+#[test]
+fn subtract() {
+    assert_eq!(
+        parse("1 - 2"),
+        Ok(Chunk::with_data(
+            vec![
+                (Instruction::load_constant(0, 0), Span(0, 1)),
+                (Instruction::load_constant(1, 1), Span(4, 5)),
+                (Instruction::subtract(2, 0, 1), Span(2, 3)),
                 (Instruction::r#return(), Span(0, 5)),
             ],
             vec![Value::integer(1), Value::integer(2),],

dust-lang/src/vm.rs

@@ -0,0 +1,231 @@
+use crate::{
+    dust_error::AnnotatedError, parse, Chunk, ChunkError, DustError, Identifier, Instruction,
+    Operation, Span, Value, ValueError,
+};
+
+pub fn run(source: &str) -> Result<Option<Value>, DustError> {
+    let chunk = parse(source)?;
+
+    let mut vm = Vm::new(chunk);
+
+    vm.run()
+        .map_err(|error| DustError::Runtime { error, source })
+}
+
+#[derive(Debug, Eq, PartialEq)]
+pub struct Vm {
+    chunk: Chunk,
+    ip: usize,
+    register_stack: Vec<Option<Value>>,
+}
+
+impl Vm {
+    const STACK_LIMIT: usize = u16::MAX as usize;
+
+    pub fn new(chunk: Chunk) -> Self {
+        Self {
+            chunk,
+            ip: 0,
+            register_stack: Vec::new(),
+        }
+    }
+
+    pub fn run(&mut self) -> Result<Option<Value>, VmError> {
+        while let Ok((instruction, position)) = self.read(Span(0, 0)).copied() {
+            log::trace!("Running instruction {instruction} at {position}");
+
+            match instruction.operation {
+                Operation::Move => todo!(),
+                Operation::Close => todo!(),
+                Operation::LoadConstant => {
+                    let register_index = instruction.to_register as usize;
+                    let constant_index = u16::from_le_bytes(instruction.arguments);
+                    let value = self.chunk.use_constant(constant_index, position)?;
+
+                    self.insert(value, register_index, position)?;
+                }
+                Operation::DeclareVariable => todo!(),
+                Operation::GetVariable => todo!(),
+                Operation::SetVariable => todo!(),
+                Operation::Add => {
+                    let left = self.take(instruction.arguments[0] as usize, position)?;
+                    let right = self.take(instruction.arguments[1] as usize, position)?;
+                    let sum = left
+                        .add(&right)
+                        .map_err(|error| VmError::Value { error, position })?;
+
+                    self.insert(sum, instruction.to_register as usize, position)?;
+                }
+                Operation::Subtract => {
+                    let left = self.take(instruction.arguments[0] as usize, position)?;
+                    let right = self.take(instruction.arguments[1] as usize, position)?;
+                    let difference = left
+                        .subtract(&right)
+                        .map_err(|error| VmError::Value { error, position })?;
+
+                    self.insert(difference, instruction.to_register as usize, position)?;
+                }
+                Operation::Multiply => {
+                    let left = self.take(instruction.arguments[0] as usize, position)?;
+                    let right = self.take(instruction.arguments[1] as usize, position)?;
+                    let product = left
+                        .multiply(&right)
+                        .map_err(|error| VmError::Value { error, position })?;
+
+                    self.insert(product, instruction.to_register as usize, position)?;
+                }
+                Operation::Divide => {
+                    let left = self.take(instruction.arguments[0] as usize, position)?;
+                    let right = self.take(instruction.arguments[1] as usize, position)?;
+                    let quotient = left
+                        .divide(&right)
+                        .map_err(|error| VmError::Value { error, position })?;
+
+                    self.insert(quotient, instruction.to_register as usize, position)?;
+                }
+                Operation::Negate => {
+                    let value = self.take(instruction.arguments[0] as usize, position)?;
+                    let negated = value
+                        .negate()
+                        .map_err(|error| VmError::Value { error, position })?;
+
+                    self.insert(negated, instruction.to_register as usize, position)?;
+                }
+                Operation::Return => {
+                    let value = self.pop(position)?;
+
+                    return Ok(Some(value));
+                }
+            }
+        }
+
+        Ok(None)
+    }
+
+    fn insert(&mut self, value: Value, index: usize, position: Span) -> Result<(), VmError> {
+        if self.register_stack.len() == Self::STACK_LIMIT {
+            Err(VmError::StackOverflow { position })
+        } else {
+            self.register_stack.insert(index, Some(value));
+
+            Ok(())
+        }
+    }
+
+    pub fn take(&mut self, index: usize, position: Span) -> Result<Value, VmError> {
+        if let Some(register) = self.register_stack.get_mut(index) {
+            let value = register
+                .take()
+                .ok_or(VmError::EmptyRegister { index, position })?;
+
+            Ok(value)
+        } else {
+            Err(VmError::RegisterIndexOutOfBounds { position })
+        }
+    }
+
+    fn pop(&mut self, position: Span) -> Result<Value, VmError> {
+        if let Some(register) = self.register_stack.pop() {
+            let value = register.ok_or(VmError::RegisterIndexOutOfBounds { position })?;
+
+            Ok(value)
+        } else {
+            Err(VmError::StackUnderflow { position })
+        }
+    }
+
+    fn read(&mut self, position: Span) -> Result<&(Instruction, Span), VmError> {
+        let current = self.chunk.get_code(self.ip, position)?;
+
+        self.ip += 1;
+
+        Ok(current)
+    }
+}
+
+#[derive(Debug, Clone, PartialEq)]
+pub enum VmError {
+    EmptyRegister {
+        index: usize,
+        position: Span,
+    },
+    RegisterIndexOutOfBounds {
+        position: Span,
+    },
+    InvalidInstruction {
+        instruction: Instruction,
+        position: Span,
+    },
+    StackOverflow {
+        position: Span,
+    },
+    StackUnderflow {
+        position: Span,
+    },
+    UndeclaredVariable {
+        position: Span,
+    },
+    UndefinedVariable {
+        identifier: Identifier,
+        position: Span,
+    },
+
+    // Wrappers for foreign errors
+    Chunk(ChunkError),
+    Value {
+        error: ValueError,
+        position: Span,
+    },
+}
+
+impl From<ChunkError> for VmError {
+    fn from(v: ChunkError) -> Self {
+        Self::Chunk(v)
+    }
+}
+
+impl AnnotatedError for VmError {
+    fn title() -> &'static str {
+        "Runtime Error"
+    }
+
+    fn description(&self) -> &'static str {
+        match self {
+            Self::EmptyRegister { .. } => "Empty register",
+            Self::RegisterIndexOutOfBounds { .. } => "Register index out of bounds",
+            Self::InvalidInstruction { .. } => "Invalid instruction",
+            Self::StackOverflow { .. } => "Stack overflow",
+            Self::StackUnderflow { .. } => "Stack underflow",
+            Self::UndeclaredVariable { .. } => "Undeclared variable",
+            Self::UndefinedVariable { .. } => "Undefined variable",
+            Self::Chunk(_) => "Chunk error",
+            Self::Value { .. } => "Value error",
+        }
+    }
+
+    fn details(&self) -> Option<String> {
+        match self {
+            Self::EmptyRegister { index, .. } => Some(format!("Register {index} is empty")),
+            Self::UndefinedVariable { identifier, .. } => {
+                Some(format!("{identifier} is not in scope"))
+            }
+            Self::Chunk(error) => error.details(),
+            Self::Value { error, .. } => Some(error.to_string()),
+            _ => None,
+        }
+    }
+
+    fn position(&self) -> Span {
+        match self {
+            Self::EmptyRegister { position, .. } => *position,
+            Self::RegisterIndexOutOfBounds { position } => *position,
+            Self::InvalidInstruction { position, .. } => *position,
+            Self::StackUnderflow { position } => *position,
+            Self::StackOverflow { position } => *position,
+            Self::UndeclaredVariable { position } => *position,
+            Self::UndefinedVariable { position, .. } => *position,
+            Self::Chunk(error) => error.position(),
+            Self::Value { position, .. } => *position,
+        }
+    }
+}

dust-lang/tests/operations.rs

@@ -0,0 +1,21 @@
+use dust_lang::*;
+
+#[test]
+fn add() {
+    assert_eq!(run("1 + 2"), Ok(Some(Value::integer(3))));
+}
+
+#[test]
+fn subtract() {
+    assert_eq!(run("1 - 2"), Ok(Some(Value::integer(-1))));
+}
+
+#[test]
+fn multiply() {
+    assert_eq!(run("2 * 3"), Ok(Some(Value::integer(6))));
+}
+
+#[test]
+fn divide() {
+    assert_eq!(run("6 / 3"), Ok(Some(Value::integer(2))));
+}

dust-lang/tests/values.rs

@@ -0,0 +1,61 @@
+use dust_lang::*;
+
+#[test]
+fn boolean() {
+    assert_eq!(run("true"), Ok(Some(Value::boolean(true))));
+}
+
+#[test]
+fn byte() {
+    assert_eq!(run("0xff"), Ok(Some(Value::byte(0xff))));
+}
+
+#[test]
+fn float_simple() {
+    assert_eq!(run("42.0"), Ok(Some(Value::float(42.0))));
+}
+
+#[test]
+fn float_negative() {
+    assert_eq!(run("-42.0"), Ok(Some(Value::float(-42.0))));
+}
+
+#[test]
+fn float_exponential() {
+    assert_eq!(run("4.2e1"), Ok(Some(Value::float(42.0))));
+}
+
+#[test]
+fn float_exponential_positive() {
+    assert_eq!(run("4.2e+1"), Ok(Some(Value::float(42.0))));
+}
+
+#[test]
+fn float_exponential_negative() {
+    assert_eq!(run("4.2e-1"), Ok(Some(Value::float(0.42))));
+}
+
+#[test]
+fn float_special_values() {
+    assert_eq!(run("Infinity"), Ok(Some(Value::float(f64::INFINITY))));
+    assert_eq!(run("-Infinity"), Ok(Some(Value::float(f64::NEG_INFINITY))));
+    assert!(run("NaN").unwrap().unwrap().as_float().unwrap().is_nan());
+}
+
+#[test]
+fn integer() {
+    assert_eq!(run("42"), Ok(Some(Value::integer(42))));
+}
+
+#[test]
+fn integer_negative() {
+    assert_eq!(run("-42"), Ok(Some(Value::integer(-42))));
+}
+
+#[test]
+fn string() {
+    assert_eq!(
+        run("\"Hello, world!\""),
+        Ok(Some(Value::string("Hello, world!")))
+    );
+}

dust-shell/src/main.rs

@@ -1,78 +1,78 @@
-// use std::{fs::read_to_string, io::Write};
+use std::{fs::read_to_string, io::Write};
 
-// use clap::Parser;
+use clap::Parser;
-// use colored::Colorize;
+use colored::Colorize;
-// use dust_lang::{parse, run};
+use dust_lang::{parse, run};
-// use log::Level;
+use log::Level;
 
-// #[derive(Parser)]
+#[derive(Parser)]
-// struct Cli {
+struct Cli {
-//     #[arg(short, long)]
+    #[arg(short, long)]
-//     command: Option<String>,
+    command: Option<String>,
 
-//     #[arg(short, long)]
+    #[arg(short, long)]
-//     parse: bool,
+    parse: bool,
 
-//     path: Option<String>,
+    path: Option<String>,
-// }
-
-fn main() {
-    //     env_logger::builder()
-    //         .parse_env("DUST_LOG")
-    //         .format(|buf, record| {
-    //             let level = match record.level() {
-    //                 Level::Error => "ERROR".red(),
-    //                 Level::Warn => "WARN".yellow(),
-    //                 Level::Info => "INFO".white(),
-    //                 Level::Debug => "DEBUG".blue(),
-    //                 Level::Trace => "TRACE".purple(),
-    //             }
-    //             .bold();
-    //             let level_display = format!("[{level:^5}]").white().on_black();
-    //             let module = record
-    //                 .module_path()
-    //                 .map(|path| path.split("::").last().unwrap_or("unknown"))
-    //                 .unwrap_or("unknown")
-    //                 .dimmed();
-
-    //             writeln!(buf, "{level_display} {module:^6} {}", record.args())
-    //         })
-    //         .init();
-
-    //     let args = Cli::parse();
-
-    //     if let Some(command) = &args.command {
-    //         if args.parse {
-    //             parse_and_display_errors(command);
-    //         } else {
-    //             run_and_display_errors(command);
-    //         }
-    //     } else if let Some(path) = &args.path {
-    //         let source = read_to_string(path).expect("Failed to read file");
-
-    //         if args.parse {
-    //             parse_and_display_errors(&source);
-    //         } else {
-    //             run_and_display_errors(&source);
-    //         }
-    //     }
 }
 
-// fn parse_and_display_errors(source: &str) {
+fn main() {
-//     match parse(source) {
+    env_logger::builder()
-//         Ok(chunk) => println!("{}", chunk.disassemble("Dust CLI Input")),
+        .parse_env("DUST_LOG")
-//         Err(error) => {
+        .format(|buf, record| {
-//             eprintln!("{:?}", error);
+            let level = match record.level() {
-//         }
+                Level::Error => "ERROR".red(),
-//     }
+                Level::Warn => "WARN".yellow(),
-// }
+                Level::Info => "INFO".white(),
+                Level::Debug => "DEBUG".blue(),
+                Level::Trace => "TRACE".purple(),
+            }
+            .bold();
+            let level_display = format!("[{level:^5}]").white().on_black();
+            let module = record
+                .module_path()
+                .map(|path| path.split("::").last().unwrap_or("unknown"))
+                .unwrap_or("unknown")
+                .dimmed();
 
-// fn run_and_display_errors(source: &str) {
+            writeln!(buf, "{level_display} {module:^6} {}", record.args())
-//     match run(source) {
+        })
-//         Ok(Some(value)) => println!("{}", value),
+        .init();
-//         Ok(_) => {}
+
-//         Err(error) => {
+    let args = Cli::parse();
-//             eprintln!("{}", error.report());
+
-//         }
+    if let Some(command) = &args.command {
-//     }
+        if args.parse {
-// }
+            parse_and_display_errors(command);
+        } else {
+            run_and_display_errors(command);
+        }
+    } else if let Some(path) = &args.path {
+        let source = read_to_string(path).expect("Failed to read file");
+
+        if args.parse {
+            parse_and_display_errors(&source);
+        } else {
+            run_and_display_errors(&source);
+        }
+    }
+}
+
+fn parse_and_display_errors(source: &str) {
+    match parse(source) {
+        Ok(chunk) => println!("{}", chunk.disassemble("Dust CLI Input")),
+        Err(error) => {
+            eprintln!("{:?}", error);
+        }
+    }
+}
+
+fn run_and_display_errors(source: &str) {
+    match run(source) {
+        Ok(Some(value)) => println!("{}", value),
+        Ok(_) => {}
+        Err(error) => {
+            eprintln!("{}", error.report());
+        }
+    }
+}